int Cmp(const void *a, const void *b)
{
    return *(int *)a - *(int *)b;
}
int maxWidthOfVerticalArea(int** points, int pointsSize, int* pointsColSize)
{
    int *tmp = (int *)malloc(pointsSize * sizeof(int));
    int count = 0;
    for (int i = 0; i < pointsSize; i++) {
        tmp[count++] = points[i][0];
    }
    qsort(tmp, count, sizeof(int), Cmp);
    int ret = 0;
    for (int j = 0; j < count - 1;  j++) {
        ret = fmax(tmp[j + 1] - tmp[j], ret);
    }
    return ret;
}

